The Eco-celli barometer consists of a 64-inch long U-shaped tube filled with a red fluid and gas. The pressure of this red fluid on the gas is principle upon which the barometer operates (Boyles Law). Adjacent to the barometer tube is a 32-inch long blue methyl-alcohol thermometer. A truly unique scale that slides between the thermometer and barometer compensates for thermal expansion of the fluid and glass tubing due to changes in room temperature and allows for accurate measurement of air pressure. Finally, the barometer scale is four times larger than a mercury barometer, making it much easier to make readings of air pressure. The temperature scale measures in Degrees F and C, while the pressure scale measures in both millimeters and inches.
The Eco-celli comes with a calibration kit to adjust the unit for an altitude above sea level. The acrylic frame and glass tubes are packaged separately in the same box and require simple assembly by the final purchaser. The Eco-celli reads sea level corrected air pressure. This is the pressure used in weather forecasting. It is not designed to read altitude specific air pressure.
The model E038.501 has been specifically designed for use in school science classrooms and school laboratories. It is made of durable clear acrylic 1/2 thick with very easy to read scales. The glass tubes are easily replaceable if broken. Additional calibration kits and red fluid are also available.
Model E038 Eco-celli Barometer
Liquid barometers definitely have a place in our schools as a teaching device allowing students to actually see the affects of atmospheric pressure on the liquid in the barometer. An electronic digital barometer cannot provide this visual reinforcement as all the students see are numbers changing, much like a digital clock. The problem with liquid barometers is that they are made using mercury, which has been proven to be an extremely hazardous material, especially to children.
In August, 1998 DD Barometers of Belgium patented the first non-mercury liquid barometer having the same accuracy as a mercury barometer in measuring sea level corrected atmospheric pressure. They named their barometer the Eco-celli after Evangelista Torricelli, the inventor of the barometer. The Eco-celli contains no mercury. The 64 inch long U-shaped glass tube is filled with a red fluid and gas. Because of the length of the barometer tube, the barometers scale is four times larger than a standard mercury scale making it much easier for a student to read. The physics involved is Boyle's Law - air pressure presses down on the red fluid which compresses the gas in the reservoir end of the barometer tube.
The precision thermometer is filled with blue colored methyl alcohol. An increase or decrease in temperature can cause the fluid in the barometer to expand and affect the pressure reading. This is corrected by setting the movable scale, which is attached to both the barometer and thermometer, to the top of the blue fluid in the thermometer.
The Eco-celli barometer costs 1/3 to 1/2 less than a comparable mercury barometer. Given the low cost and non-mercury operation, replacing mercury barometers in the classroom now is a sensible option. Each mercury barometer contains approximately one pounds of mercury and most middle, high schools and colleges in the nation have at least one, if not many more. By replacing these barometers, we could remove tons and tons of mercury from ever becoming an environmental hazard.
The new E038.501 acrylic model pictured is the model we recommend for school use.